Electrode-cooling construction



Dec. 9, 1924. I 1,518,416

H. M. sT. JOHN ELECTRODE COOLING CONSTRUCTION Fi-led Oct. 10, 1922 Patented bee. 9, 1924.

PATENT OFFICE.

UNHTED STATES HARRY M. ST. JOHN, 0F DETROIT, MICHIGAN.

ELECTRODE-COOLING CONSTRUCTION.

Appflication filed October 10, 1922. Serial No. 593,644.

To aZZ whom it may concern:

Be it known that I, HARRY M. ST. JOHN, a citizen of the United States, residing at Detroit, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in Electrode-Cooling Constructions, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

,This invention relates to improvements in means for counteracting the tendency to undue heating on the part of electrodes used for heating the metal .under treatment in electric furnaces, and has for its object an improved organization of parts by means of which a cooling coil may be supported in position thereabout and all of the parts suitably insulated from the structural frame parts of the drum as a whole.

In the drawings:

Figure 1 is an end elevational View of that portion of a furnace wall end immediately surrounding the electrode.

Figure 2 is a sectional elevation, taken along the line 22 of Figure 1.

A represents a casting mounted upon the end facing plate D of a rocking or rotatable furnace drum, through whose axial center the heating electrode B is projected into the interior of the furnace to the desired degree for the formation of an are between its inner end and that of its companion electrode, which similarly projects through the other end wall, each being thus held in equidistantly spaced relation to the surrounding side wall Q3 of the refractory drum. Of course, the active inner ends of the electrodes are necessarily raised to a high degree of heat when a current-induced arc is passing from one to the other, but it is desirable that the rear end of each electrode, both that portion which projects outside of the furnace drum and thatimmediately within enclosing cap or plate E, be kept at as low a temperature as possible, to avoid too rapid disintegration. To this end resort has already been had to the positioning about that portion of the electrode just within the insulating plate E of a cooling coil C, Whose ends F, reaching outside of the drum, are connected with a suitable water-cooling circuit, which thus tends to reduce the otherwise high temperature prevailing within that portion of the electrode which it surrounds. Great difficulty has, however, been experienced in so associating this cooling coil with the furnace drum walls as to hold it firmly in position in spite of the rocking or rotat-' ing movement of the furnace and at the same time to suitably insulate it from the necessary and quite closely positioned metal parts of the furnace frame.

To this end, I provide on the insulating plate E projecting ear pieces 'P, which may be bolted to the collar K, which is in turn secured on the metal frame G in such position that its aperture is truly coaxial with the furnace drum as a whole and with the electrode B, which projects therethrough. On one edge of the plate E, I locate a plate H, also of suitable insulating material, which is attached by means of the bolts J to suitable fianges on the collar K, and through which the cooling tubes F pass, being held firmly in position by their tight engagement through the apertures therein, while the inner end of the coil is suitably anchored by the use of a mass of insulating cement M in the recess in the adjacent end of the refractory section L. There is thus provided inside the plate E a space N in which granular insulating and protecting material may be packed about the cooling coil 0 or, it may be entirely omitted, so that to the greatest degree consistent with its efiicient action upon the electrode B, it is protected from undue heating. This construction makes it possible to hold the coil so rigidly in place about the electrode that the escape of vapor from the molten metal within the furnace drum is reduced to a minimum, as well as more perfectly insulating the coil as a whole from the furnace shell, since the provision of the plate in spaced relation to the refractory drum end provides an additional space longitudinally of the electrode, along which its fit in the furnace wall apertupre is quite close, thus allowing, and making compensation for, a possible diminution in the thickness of the furnace wall due to chipping off and abrasion when in use.

What I claim is:

1. In combination with a centrally apertured refractory furnace wall, a plate having a central aperture held in position of closure thereover, a cooling coil held on the inner side of the plate in coaxial relation to the apertures in the wall and the plate, the

terminals of said cooling coil extending through an insulating fianging projection on said plate and being held thereby against unintended displacement due to the operating movement of the electrode through the coil and said apertures.

2. In combination with a terminally apertured refractory furnace drum, a centrally apertured closure plate positioned across said apertured portion of the drum in position for the regulated longitudinal movement of an electrode therethrough, an insulating plate supported adjacent one edge of said closure plate, and a cooling coil Whose inlet and outlet end portions extend through said insulating plate, supported thereby in encircling position relatively to that portion of the electrode which extends interiorly of said closure plate.

3. The combination, with a terminally apertured furnace wall, of a holding collar piece adjacent the edges of said aperture, an apertured closure plate supported by said collar piece, and an electrode cooling coil .epositioned interiorly of said closure plate about an electrode projected through the aperture therein, said cooling coil being firmly held in position by the engagement of its externally extending end portions, through an edge portion of said closure )late. I l 4. In combination with an apertured furnace Wall, an apertured closure plate of insulating material, a collar member whereby said closure plate is detachably secured to said furnace wall, and an electrode cooling coil supported by said plate in encircling position about the interiorly projecting portion of an electrode which adjustably engages through an aperture in said collar, through a projecting flanged portion of which the ends of said cooling coil extend to connection with an external source of coolinf fluid supply.

In testimony whereof, I sign this specification in the presence of two witnesses.

HARRY M. ST. JOHN. lVitnesses VILLIABI M. SWAN, JEFFERSON G. THURBER. 

